Dow Wetlands Preserve marks 25-year anniversary

Turtles soak up the sun on a beaver pond float. (Joan Morris/Mercury News)

The other day I took about a 4-mile hike through the Dow Wetlands Preserve in Antioch, and I still didn’t see all of it.

The site is about 470 acres, from Kirker Creek to the Antioch Marina, the boundary of 10th Street on the south and the Delta on the north. At the invitation of preserve volunteer Krist Jensen, I walked along with some other volunteers to discover this jewel that originally was purchased in 1989 for $11 million by nearby Dow Chemical to create a buffer zone alongside the plant.

Some environmentally minded folks, however, decided that just being a buffer wasn’t good enough, and the marsh and wetlands that once supported a hay growing farm, were restored to a more natural state. The preserve has more than 170 acres of freshwater/brackish tidal marsh plus a 30-acre beaver pond, freshwater ponds, open water, mudflats, riparian zones, uplands and grasslands. The pond is now home to beaver, river otters, mink and a variety of water birds. The otters and beavers have carved water pathways through the marsh, allowing them easy movement to food and building material, and migratory birds stop by on their journeys to visit the permanent residents.

The wetlands, profuse in pickle weed, also are home to the endangered salt harvest marsh mouse, and to two California native plants considered rare and endangered, the Lilaeopsis masonii, a species of flowering plant in the carrot family and known commonly as mudflat quillplant or Mason’s lilaeopsis; and Aster lentus, a dicot perennial herb also known as Suisun aster.

Beavers have created canals through the tules. (Joan Morris/Mercury News)

Walking along the trails cut through cat tails and reeds, or strolling along a winding, shady path in an area affectionately known as the jungle, you can lose yourself in nature. The quiet is broken only by the sound of birds or the splash of geese, turtles and otters, or the whistle of a train that rumbles through the property. The volunteers — about 40 of them — maintain the preserve with care and love. They scavenge scraps of wood to build observation towers and platforms; one enterprising man found three stadium chairs listed for free on Craigslist and has now planted them solidly in a meadow overlooking the Delta. They also maintain the trails, building bridges across the swampier areas. The lucky ones find themselves spending hours at the preserve, working hard but hardly noticing. They are entranced by nature.

It’s a magical place, open to all for free, in the hours between dusk and dawn. A weekly hike, I imagine, would reveal a changing environment as plants grow and the marsh shifts in its muddy bed.

The main entrance is located on 10th Street, near the Dow main gate. You also can access it from the Antioch Marina parking lot. If you’d like to be more than just a visitor, the volunteers can always use a helping hand. If you’re interested, call Dow at 925-432-5576.